from selenium import webdriver
from selenium.webdriver.support.ui import Select

driver = webdriver.Chrome()

driver.get('http://cdn1.python3.vip/files/selenium/test2.html')
# 多选框
#select = Select(driver.find_element_by_id("ss_multi"))
select = Select(driver.find_element_by_css_selector('#ss_multi'))
# 清除所有选中项
select.deselect_all()

select.select_by_visible_text('小江老师')

select.select_by_visible_text('小雷老师')